# All Questions

8,693 questions
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### Why should the Kármán line not be a realistic, curved one around the Earth?

Why not consider the Kármán line as a curved one that follows the curvature of the Earth ? According to Wikipedia's article about the Kármán line: The Kármán line is the altitude where the speed ...
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### What advances are there in heat-resistant materials for engines?

As one of the difficulties in engine design is to prevent it from melting, one can expect research to be conducted on what materials to use for thrust chamber and nozzle. Many engines seem to use ...
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### What is meant by chamber pressure in rocket engines?

Is "chamber pressure" the pressure at the tip of the injector, or the pressure before combustion inside the chamber, or the pressure after combustion inside the chamber?
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A transponder amplifies, (often) frequency-shifts, and rebroadcasts a received signal. Old-style telephone and TV distribution satellites in GEO used simple transponders to rebroadcast the uplinked ...
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### Did NASA's Borg Collective-designed antennas work? Have similar designs ever been used in spacecraft beyond testing?

This interesting answer to the question Do antenna farms on spacecraft make any sense or are they purely aesthetic? in Worldbuilding SE links to the NASA Ames page 'Borg' Computer Collective Designs ...
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### How will “InSight's onboard communications gear perform a radio-science experiment to shed further light on Mars' innards?” (Space.com)

The Space.com article How NASA Mars Lander's 'Steampunk' Claw Will Work (Video) says: InSight's mission aims to provide a detailed look at Mars' interior structure and composition. The lander ...
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### Temperature indicators/labels on space debris?

There was a picture in this question about space debris on shore. Seems to be a part of a Falcon 9. The round stickers are used for temperature control. Similar labels are sold by some companies, for ...
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### What would be the specific impulse of a continuous nuclear fusion drive?

Let's assume problems of running sustained nuclear fusion are overcome (be it by making the mechanism highly energy-positive, or just supplying all the energy deficit externally, like beamed power.) ...
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### Who performs the docking procedure?

In the Apollo moon missions when the LEM returned to the CSM, which astronaut performed the docking procedure? Did the command module pilot just hold a fixed position while the astronaut flying the ...
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### Would the atmosphere of Mars become less dusty if the ice deposit in Utopia Planitia could be uncovered?

In 2016 a large ice deposit has been found within the Utopia Planitia region on Mars by the SHARAD instrument on board of the Mars Reconnaissance Orbiter. The thickness of the deposit ranges from 80 ...
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### Venus Exploration [duplicate]

While reading an article about a possible "Cloud City" on Venus I was taken by the following statement: Venus’s atmosphere is mainly carbon dioxide and thick clouds of sulfuric acid cover the ...
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### What is the typical mach number at which the peak dynamic pressure occurs?

Is there any mach number range (say 0.8-1.4) where the maximum Q of the rocket should occur?
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### Wet space junk and flotsam washing up on shore, will it get worse, is there a plan to mitigate?

This comment links to this collectspace.com post: Three business executives vacationing (?) in the Bahamas came across part of a SpaceX Falcon 9 fairing that washed ashore. They shared their find ...
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### Any risk from Soyuz 22-ton fuel dump?

Following the recent mishap with the Soyuz, Kazakhstan's deputy minister for defense and the aerospace industry said that about 22 tons of fuel (kerosene and liquid oxygen) were dumped/fell over the ...
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### NASA's Curiosity Rover - Carbon Isotope Ratio of Methane?

The following is taken from Sinha & Rral , 2015: "NASA's Curiosity rover has the capability to search for organic compounds and to identify the chemical and isotopic composition of the Martian ...
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### NRLMSISE atmospheric drag model in GMAT

I'm using GMAT (R2018a) software for orbital propagation and now testing the atmospheric drag. There are only 2 options: JacciaRoberts and MSISE90. Is there a way to add NRLMSISE00 to the options? ...
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### What is the highest gimbal range ever used on an engine?

This answer here mentions the STS-94's ability to gimbal up to 20 degrees in all directions, that got me thinking, what exactly is the maximum ever feasibly implemented? I've seen a lot of information ...
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### How much would mass-production impact the cost of solid-fuel rockets?

Let's imagine that, for some arbitrary reason, solid-fuel rocket stages were needed and built en masse in factories, like planes or even like cars. How much would it drive down the cost of an ...
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### Unknown Moons and Planetary Flybys

I’ve a question for any trajectory experts out there: The Pioneer and Voyager probes discovered new moons during their flybys of our four giant planets (and indeed rings). These didn’t come as much ...
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### How was the thrust for the STS-94 launch and other space shuttle launches balanced? [duplicate]

I've been looking at of the STS-94 skylab launch and other launching involving asymmetrical rocket launch vehicles, mostly because I've never been able to design something similar in KSP with ...
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### Orbital Strap-on Boosters?

Have there been any proposals to launch a "space station" type of assembly into LEO, then send up some engines to get it to be able to move again? Take for instance something akin to the ISS, but much ...
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### What did Karman's original “Karman line” calculations look like?

Looking for the atmospheric parameters (density for example) and vehicle parameters (CL for example) as well as formulae that were used in the original calculation. Primary sources strongly preferred,...
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### Did the Soviet Union put an unmanned satellite in “very low orbit”above the Kármán line which used aerodynamic attitude control?

This interesting, archived page https://www.webcitation.org/618QHms8h?url=http://www.fai.org/astronautics/100km.asp which I found in this answer, says: Later in the same decade (or very early in ...
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### How did the X-15 control attitude above the Kármán line?

This interesting, archived page https://www.webcitation.org/618QHms8h?url=http://www.fai.org/astronautics/100km.asp which I found in this answer, says: In the early 1960´s, the U.S. X-15 Aircraft ...
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### How are rocket propellants ignited repeatedly without the ignition source melting

I know that SpaceX's Falcon uses TEA-TEB instead of a physical igniter, but if I remember correctly, NASA has never used hypergolic propellants to start their restart-able engines. How does NASA's (or ...
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### Analytical approximations for the shapes of these plots of ISP vs nozzle diameter? (Raptor engine)

A comment on the currently unanswered question Is there an authoritative catalog for rocket launch identifiers? led me to this Github page which links to r/spacexlounge on which currently appears a ...
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### Orbital propagation: atmospheric drag

I'm developing the numerical orbital propagator. I've already implemented the Newtonian gravity (Earth, Sun, Moon), Earth harmonics, SRP and relativistic effect. The software is compared with GMAT ...
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### Why not keep the engine for multi-stage rockets?

Rocket engines are a huge weight in a multi-stage rocket. and they are stacked like so: Fairing/Payload Fuel Engine -- Seperator -- Fuel Engine and so on, which means multiple engines. Is there ...
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### How accurate can a satellite's orbit be?

How precise can an artificial satellite be when it comes to following the exact orbit in relation to Earth or hitting the same point above Earth in orbit? Which orbit would be the most stable for this?...
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### What is the speed of ISS relative to ground surface?

Is it 7660 m/s or (7660-460)m/s? If it is the former then the ISS orbits about the Earth at 8120 m/s. I think it should be (7660-460)m/s relative to ground based on this orbital period formula, T=...
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### NASA's Mars helicopter blade & weight

I've been really interested in NASA's Mars helicopter and have been reading bits of articles on that recently. But I have a few questions I hope people can help me understand — in this article, it ...
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### Why does in-flight mission abort often ends in ballistic high-$g$ reentry?

I am seeing a lot of references to the “ballistic reentry” mode of the crew return vehicle in relation to the abort during the powered ascent stage. In partiulat, the recent crewed Soyuz MS-10 abort ...
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### Is there an orbit that follows the polar cusp?

What orbit would follow the polar cusp in the magnetosphere demonstrated in the picture below in red? What altitude would be needed to stay in the polar cusp following the Sun?
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### Has the answer to PopSci's question “How Many Years Does The Space Station Have Left?” been published?

This answer to the question Why does the ISS have to be destroyed? begins It doesn't, not really, but there will come a time when it will simply not be worth keeping it up. and mentions a study, ...
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### What is the likely plan to deorbit the ISS given its size and shape?

The ISS is nearing its final years and this question spurred me to ask a follow up. Let's say that the various countries grab whatever equipment/modules they provided in assembly and the ISS is ...